1. Field of the Invention
The disclosures herein relate to a liquid-jet head, an image forming apparatus having the liquid-jet head, and a method for manufacturing the liquid-jet head.
2. Description of the Related Art
An inkjet recording apparatus is generally known as an example of a liquid-jet recording type image forming apparatus, such as a printer, a facsimile machine, or a plotter, or a multifunctional peripheral having combination of these functions. The inkjet recording apparatus includes a recording head formed of a liquid-jet head (liquid-drop jet head) that ejects liquid drops.
There is disclosed, as an example of the liquid-jet head, a piezoelectric head including a deformable diaphragm member forming at least one wall surface of a liquid chamber in communication with nozzles ejecting liquid drops, and a multilayered piezoelectric element configured to pressurize a liquid inside the chamber by the deforming diaphragm member.
Japanese Patent No. 3374899 (hereinafter referred to as “Patent Document 1”) discloses an example of such a diaphragm member utilized in the piezoelectric head. In this example, the diaphragm member includes a thick part (i.e., an island-shaped projection part), and a thin part formed in the periphery of the island-shaped projection part. In the diaphragm member, photosensitive resin is formed such that the photosensitive resin covers an outer surface of the island-shaped projection part, and further reaches a part of the thin part, thereby reducing stress concentration applied to a circumference of the island-shaped projection part with concentration due to expansion and contraction of the piezoelectric element.